Hi,
the main point:
pigments (and maybe enamel itself) in the interior pot coating are partially made from metals.

I looked at Le Creuset's stockpots.
The color of the inner enamel was beige.

Le Creuset or similar enameled products, is said to be "the world's safest", "an inert ,non-reactive".
I'd be much interested in such. I want to avoid secretion of metals or toxins into the food I cook. (aluminum, nickel, teflon etc.)

Pigments: I assume, that the same pigments for glass are used for the enamel.
many of them are made from metals, which some are poisenous. (besides "lead and cadmium")
also mentioned "organic binder" as taking part of the process.

As far as the toxicity of metals is concerned I can allay your fears about a few metals you listed. First, titanium has been used in orthopedic and oral surgery for sevaral decades now many joint replacements and virtually all dental implants are titanium. Titanium oxide in its three forms TiO, TiO2 and Ti2O3, zirconium and zirconium oxides (I'm less familar with oxides of zirconium) are all very biocompatible. The body responds very well to them by actually forming biological attachments to their surfaces, which is how dental implants essentially fuse to the jawbone. Aluminum has a bad rap because of its being found in CNS tissue of Alzheimers patients, but it is unclear whether that is a CAUSE OR RESULT of the disease. Anyway aluminum has been used in various implants in alloys with titanium and vanadium (grade 5 titanium alloy--which is 90% Ti, 6% Al, 4% V and is extremely strong) and has also been succesful and biologically compatible from clinical and histological criteria. As an alloy, it is possible but unlikely that significant aluminum leaves the parent metal to a biologically significant degree at body temperature. The oxides on the titanium surface and its alloys are stable and protect the parent metal from corrosion. Titanium is also commonly used in "body jewelry" because of its biocompatibility.

You are on your own regarding other metals you listed e.g. barium, strontium, lead, lithium, bismuth, boron, etc, but I can say that Barium sulfate is not absorbed by the GI tract and that boron (usually encountered as boric acid or borates) is not listed as one of the materials toxic to humans in day to day encounters.

But just for the record, enamel is a complex composite,
and boro-silicate (pyrex) glass is less.

All those enamel elements require further reading, and I don't think
there is a conclusive evidence to say that they aren't toxic.
After all, the health establishment say that mercury in amalgam isn't toxic , and fluorine is good for humans.

By using glassware, you deal with less elements, and they seem to
be more friendly to humans.

But just for the record, enamel is a complex composite,
and boro-silicate (pyrex) glass is less.

All those enamel elements require further reading, and I don't think
there is a conclusive evidence to say that they aren't toxic.
After all, the health establishment say that mercury in amalgam isn't toxic , and fluorine is good for humans.

By using glassware, you deal with less elements, and they seem to
be more friendly to humans.

But glassware is not friendly to the cooker...

The jury is still out on mercury in amalgam, and if mercury concerns you, you MUST stop eating fish, especially those longer than ten to twelve inches in length. You get so much more mercury from eating fish than you could ever get from amalgams in your mouth, you can't imagine. As far as fluorine is concerned, fluoride (not fluorine, the gas) is good for your teeth AND for your all your bones, especially when ingested at a rate of 0.5 to 1.0 mg per day when teeth and bones are forming, which means from shortly after conception through about age 20 or so and thereafter. Calcium fluorapatite is much more resistant to dissolutiion than calcium hydroxyapatite, which is very helpful in preventing dental decay and osteoporosis--and that is without the problems caused by bisphosphonates used for treating osteoporosis.

All in all, unless we figure out how to live on another planet, we are all eventually going to be very dead on this one for a long, long time. While I do not condone being reckless, (like cooking in pewter) the cooking vessels we normally consider to be non-reactive are safe to use and do not pose a health risk, and will allow us to live very long, healthful lives. There are a lot of risk factors many people have that are far worse than using certain cooking vessels. We do need to cook in something! At this time, enamel, glass, stainless steel and cast iron (reactive, but safe for certain foods), and non-sticks as long as you don't overheat them, are what we have to use. Uncoated aluminum is the main no-no in my book.